Pressure-regulating valve for lubricating apparatus



April 21, 1931. E. w. DAVIS PRESSURE REGULATING VALVE FOR LUBRICATINGAPPARATUS Filed Juiy 15. 1927' ww W ` a pressure regulating device o fPatented Apr. '21, 1931 UNITED STATE-s 4PMlazNT OFFICE maar w. Davia-oirou rank, innnronsx,l nssicNoga. ro ammira CORPORATION, or

cmcaeo, rumors, n oonroaa'rioiz or DELAWARE BEGULATING VALVE FOBLUBBICATING APPARATUS Application led' July 15, 1927. Serial No.205,981.

My invention relates generally to lubricating apparatus, and moreparticularly to devices for regulatin the pressure in the dischargeconduit o power operated high 5 pressure lubricant compressors.

My invention contemplates the provision of a device for preventing thepressure in the discharge conduit from exceeding a certain predeterminedmaximum ressure, and

o opening a by-pass from the discharge conduit to the lubricant supplrreservoir whenever the pressure in the ischarge conduit exceeds thepredetermined limit.

It is an object of my invention to rovide this type which will reducethe power consumption o the `compreor whenever lubricant is not beingforced from the discharge conduit.

It is a further object of my invention to. provide a device which willautomatically control the lubricant compressor continuously to maintaina certain predetermined pressure on the lubricant in the dischargeconduit.

A further object of my invention is to provide a device of this class,which is simple in construction, effective in operation, economicallmanufactured.

Other ob]ects ,will a pear from the following description, re erencebeing had to the accompanying drawings,-in which Fig. 1 is an elevationof a power o erated lubricant compressor unit, parts of t e cas- 35 ingbeing broken away to s ow the internal construction thereof, and 'j Fig.2 is an enlarged central vertical cross sectional view of the pressureregulating device of my invention.

In lubricant com ressors, as used in garages and industrial. plants, anelectric motor or othersuitable motor is frequently uscdto drive thepump which places the i lubricant under pressure.- The dischar 45 fromthe pump -is intermittent,that is, t e

reliable, eicient and and which may be lubricant discharge conduit issuccessively connected to each of a plurality of bearings,

andduringthe time that the connections are being made,and also while theapparatus is being moved from one machine to another, it is inconvenientto shut off the supply of electriccurrent to themotor. One method ofoperation is to permit the motor to run continuously and to' provide a'safety valve to permit by-passage of the lubricant from thedischargeconduitv to the reservoir as soon as the pressure in the dischargeconduit builds up to a predetermined linut. In utilizing this method ofcontrolling the pressure in the discharge conduit, the pump workscontinuously against high' pressure, thereby maintaining a continuousheavy c load upon the motor, with the result that the currentconsumption is 'much' greater than necessary, and that the life of themotor and connecting gearing is proportionately shortened.

My invention contemplates the provision: of a device which will maintainthe pressure in the discharge conduit at a predetermined high pressureand yet 'permit the pump to work against a very low pressure after thepredetermined pressure in the discharged conduit has been attained.

In Fig. 1 l have illustrated a conventional electric motor drivenpumping outt to which the pressure regulating device of my invention hasbeen applied. The outfit is Imounted as a unit upon-a suitable base 4,

which may be permanently secured to a suitable foundation or may bemounted ufpon casters. A'motor 6 havinga rotor sha 8 is mounted uponthis base casting, the shaft 8 being connected to a worm'drive shaft 10by any suitable4 flexible. vconnection 12, A worm 14 is keyed orpinned-to theshaft 12 and meshes with aworm gear 16 secured to a crankshaft 18. A pump` plunger -20 hav' ing an enlarged slide ortion 22 isconnected to the crank shaft 18 y a suitable connect' 9 ing rod 24. Theportion 22 slides freely in a cylinder 26 formed in a casting 28, whichis secured to the base cast-ing 4. This cast- V ing 28 also has aplunger Cylinder 30, which communicates with the inside of a container32 through an inlet port 34. The container has a suitable' cover 36, andis provided with filled, and has suitable projections at its lower end,so that the follower 40 may easily be withdrawn from the container whenthe latter is to be refilled.

The pressure regulating device of my invention is best illustrated inFig. 2, and comprises a body 42 in which chambers 44 and 46 are formed.The body 42 has a threaded portion 48- screwed into the end of thecylinder 30. Its chamber 44 contains a spring pressed ball check valve50 preventing return liow to the pump cylinder through the bore 52.Chambers 44 and 46 are connected by aduct 54, which is normally closedby a spring pressed .ball check valve 56, the spring 58 of which isseated upon a suitable shoulder formed in a T connection 60,- Which is`threaded into the end of the body 42.` A discharge conduit 62 isattached-to the connection 60 in a suitable manner, and at its other endcarries a suitable coupler 64 by which a quick detachable connection maybe made with the fittings 61 of bearings 63 which are to be lubricated.This coupler may be of any well known type comprising a valve which isopened to permit the passage of lubricant after the coupling operationhas been completed, which valve closes upon detaching`the coupling ,fromthe lubricant receiving fitting. In lieu of a valvedcoupler, a valvelesscoupler is often used, in which case a suitable manually controlledvalve is used near the coupler to control the flow of lubricant from theconduit.

The T connection 60 is threaded to receive a pipe or other suitableconduit 66 which leadsto the upper end of a cylinder 68. The upper endof the cylinder is closed by a suitable threaded plug 70, while thelower end 'has a small bore 72 forming a guide for a stem 74 carried bya cup leather piston 76. A sprin 78 normall forces the piston upwardly.packing g and 80 with suitable packing'82 prevents leakage of lubricantpast the stem 74. The` lower end of the stem 74 .protrudes within achamber 84 formed in a tubular support 86, which is threaded in a' boss88 formed at the top of the body 42, and has -its upper end internallythreaded to receive the lower endl of the cylinder 68. The tubularsupport -86 has a spring pressed ball valve 90 normally reventing flowof lubricant from the chamer 44 through a port 92 into the chamber 84.The chamber 84 is connected to the conimproved pressure regulatorovercomes this tendency and at the same time maintains the desiredpressure in the discharge conduit.

During normal operation when lubricant is being discharged from theconduit 62 lubricant will flow directly past check valves 50 and 56 tothe conduit and the remaining parts will be in the positionssubstantially as shown in Fig. 2. When the valve at the coupler 64 isclosed, the pressure will quickly build up in the conduit until itreaches the predetermined maximum limit, which, for' illustrativepurposes, will be assumed to be 1,000 pounds per square inch. As thepressure rises, lubricant will be forced through the pipe 66 into thechamber 68, and -force. the plston 76 and stem 74 downwardly. againstthe resiliency of spring-78. When the pressure of 1,000 pounds persquare inch is reached, the end o the stem 74 will con- 4tact with anddepress the ball valve 90,

thereby permitting free passage of the lubricant rom the pump cylinderpast the check valve 50 through the bore 92 ast the valve into thechamber 84 an thence through the pipe 94 into the reservoir 32. It willbe noted that the resistance to flow through this passage isvery slight,being only of the amount necessary to opening check valve 50 andovercome the negligible friction of the passageways. The motor thus doesvery little work, with-consequent reduction in the amount of electricityconsumed and in the Wear on the motor and driving parts. The check valve90 will prevent return flow of lubricant in the conduit and the pressuretherein will thus remain at 1,000 74 will hold the valve 90 open as longas the pressure of 1,000 pounds per square inch or more is maintained inthe conduit. As soon as the pressure drops below 1,000 pounds per squareinch, the spring 78 will pounds per square inch. The stem.

force the piston 76 upwardly, thereby with- As previously pointed out',this system and I device for regulating the lubricant pressure pressureAmaintained vin the conduit is de' pendent upon the size offthe piston76 -and its cylinder, the resiliency of the spring 7 8 and the size ofthe port of the valve 90. Either one or several of these factors may bevaried to increase or decrease the maximum pressure limit. The cylinder68 is made separable from the remaining parts ofJ the regulator, so thatif a different maximum pressure is desired, a cylinder, piston, stem,and spring having the desired characteristics' may be substituted as aunit.

While I have shown and described but a single embodiment of myinvention, it will be apparent'to those skilled in the artthat variousmodifications thereof may be made without departure from the rinciplesof my invention, and that while lphave described the invention as usedwith lubricating apparatus, tov which use it is `particularly`adapted,'the device may be used inl many other ways. I therefore wishthe scope of my invention to be limited only by the claims which follow.

1. Ina high pressure lubricating system having a reservoir and'acontinuously driven pump supplied with lubricant therefrom, thecombination of-a valved discharge conduit adapted intermittently topermit escape of lubricant therefrom and adapted to be lWardly openingvalve in said connected to the outlet of the pump, two check valves insaid discharge conduit, a passageway leading from the space between saidcheck valves to said reservoir, an inassageway, and lost motion meansactuated y the pressure in said conduit beyond said check valves foropening said valve when a predetermined pressure is attained in saiddischar e conduit. 2. a high pressure lubricating system having areservoir and a continuously driven pump supplied with lubricanttherefrom, the combination of a valved discharge conduit adaptedintermittently to permit esca e of lubricant therefrom and connected tosaid pump, a pair of check valves in said discharge conduit, a passageleading from the space between said check valves, an in-l wardly openingvalve in said passage, a

iston and cylinder connected to said conuit at a point beyond said checkvalves and a stem carried by said piston and adapted to contact with andopen said last named valve Whena predetermined pressure is attainedinsaid discharge conduit.

3. In a high pressure lubricatin system having a reservoir and acontinuous y driven pump supplied with lubricant therefrom,

the combination of a discharge conduit adapted intermittently to permitescape of lubricant therefrom and' connected to said pump, a pair ofvalves in series 'in said discharge conduit, a passage leadingi from-thespace between said valves to v reservoir, an inwardly opening pressurerelief valve in said passage, piston means actuated b the lubricantpressure in a portion' of sai conduit beyond said pair of valves, and alost motion connection between said piston means and'said relief valve,said pis,-

ton means and-connection being adapted to open said relief valve when apredetermined pressure is attained in said portion of said dischargeconduit.

4. In a high pressure lubricating system having a continuously.operating motor and a pump directly connected thereto, the combinationof a pair of check valves in series at the outlet of said pump, avalved'discharge conduit having one end connected to the outlet of saidpump, the other end there-- of being adapted to be successivelyconnected to a plurality of receiving devices, and means to preventexcess pressures in said conduit andrelieving thepressure at the outletof said pump between said check valves, comprising an inwardly openinghaving two valve seats, spring pressed outwardly opening check valvesnormally resting on said seats, a by-pass outlet between said check-valves, an inwardly opening spring pressed closure normally closingsaid by-pass, a cylinder secured above said closure, a spring pressedpiston reciprocable in said cylinder, a stem secured to said piston andprojecting through the lower end of said cylinder into a chambercommunicating with said reservoir, said stem having its end in ali entwith and normally spaced a short distance above said closure, and aconnection from a point beyond said outwardl opening check valves tosaid cylinder w ereby said piston and stem will be forced downwardl toopen said by-pass closure upona pre etermined pressure withoutmaterially decreasing the pressure at said oint. a

6. n a high pressure lubricating system Vhaving a 'reservoir and pumpingmeans adapted to deliver'lubricant `at constant pressure connected tosaid reservoir, the combination of a discharge conduit c011- `nected tothe outlet of said means, a pair of outwardly opening check valves inseries in said outlet, a by-pass to said reservoir `from. said outlet ata point between said check valves, an inwardly opening closure in saidbypass, and piston and cylinder meansoperated by the pressure in saiddischarge conduit for openlng said by-pass'closure, said last-namedmeans being removable as a unit from the combination.

. In witness whereof, I hereunto subscribe my name this 9th day of July,1927.

. ERNEST W. DAVIS.

